Wikipedia
HIO
HIO may refer to:
- Hillsboro Airport, Washington County, Oregon, USA
- Hypoiodous acid (HIO), an oxidising agent
- Oslo University College (Norwegian: Høgskolen i Oslo, HiO), the largest state university college in Norway
- Østfold University College (Norwegian: Høgskolen i Østfold, HiØ), a further and higher education institution in south-eastern Norway
- Tsoa language, spoken in Botswana and Zimbabwe
- Highly Inclined Orbit, a satellite orbit in a plane tilted far from the equatorial plane